In transport refrigeration systems, such as are used in truck trailers and refrigerated containers, a diesel engine is provided to drive certain components such as the compressor and the generator for the refrigeration system.
While operating in high altitude conditions, the inadequacy of air to the engine when more power is called for may cause the engine to stall. This problem is commonly addressed by the use of a manifold absolute pressure (MAP) sensor in the air intake system and using it to control the power required by the unit, which in turn would prevent the engine from stalling.
A separate, and unrelated problem is that of the intake air filter being clogged after extensive use. This problem has generally been addressed by the use of a so called “filter minder”, which is a simple visual pressure indicator which shows when an air filter is plugged and needs to be cleaned or replaced.